<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const a = [1,2,3,5]
        const b = [1,3,5,6]
        const num = []
        a.map(item=>{
            const m =b.some(e=>item===e)
            if(!m) num.push(item)
            return num
        })
        //console.log(num);
    </script>
</body>
</html>